Railway-traffic-controlling apparatus



Aug. 28, 1923.

R. A. MQCANN RAILWAY TRAFFIC CONTROLLING APPARATUS 3 Sheets$heet 1 INVENTORZ Q K?/ a ATTORNEY NEE m n w v Hv \i H a w H 6 bwww Q m w U R. A. M CANN RAILWAY TRAFFIC CONTROLLING APPARATUS Aug. 28, 1923. I meme-,5

. Original Filed 001;, 4, 1922 Sheets-Sheet 2 a' X'MZ w 1 4:. ATTORNEY Aug. 28, .1923;

R. A. M CANN RA 1 LWAY TRAFFIC C ONTROLLI NG APPARATUS Original Filed Oct. 4. 1922 5 Sheets-Sheet 5 INVENTOR v ,2 a BY Z'i'fhvw ATfoRNEY lllllllllllrlll III iaeaesii RONALD A. IiIoCANN OI SVJISSVALE,PENNSYLVANIA, ASSIGNOR TO THE UNION SWITCH & SIGNAL GOMI ANY, OFSv- J'ISSVAL'E, PENNSYLVANIA, A CORPORATION OF PENNSYLVANIA.

RAILWAY-TBAFFIC-OON'IROLLING .APPARATUS,

Continuation: of application Serial No. 592,444, filed October 4,

1922. This application filed December 29, 1922. Serial No. 609,723,

To all whom it may concern Be it known that I, RONALD A. MCCANN,"

which traffic moves in both directions and which are provided with passing sidings.

In systems of the type referred to, means are usually provided for giving one inch-- cation or another on a train approaching a siding when the block beyond the siding is occupied, the indication depending on whether the train in the block beyond the siding is moving towards or away from the siding. One feature of my invention is the provision of novel and improved means for preventing a change from a higher speed indication to a lower speed indication aboard the train, due to a train entering the block ahead, when the first train is approaching the siding under a proceed signal indica tion.

The present application is a continuation of my co-pending application filed on the 4th day of October, 1922, Serial No. 592,444, for railway traiiic controlling apparatus, in so far as the subject-matter common to the two is concerned, the said co-pending ap plication being a renewal of my application filed on the 28th day of May, 1920, Serial No. 384,830. I

I will describe one 'form of apparatus embodying my invention, and will then point out the novel features thereof in claims.

In the accompanying drawings, Fig. 1

provided with roadside signals controlled in accordance with one usual and well known method. Figs. 2 and 2, when placed end to end in the order named, constitute a diagrammatic view showing one arrangement of apparatus embodying my invention and adapted for use in conjunction with the is. a view showing a stretch of railway track IIQ QClSidG signal arrangement shown in bimilar reference characters refer to similar parts in each of the several views;

Referring first to Fig.1, the reference characters 2 and 2 designate the track rails of a stretch of single trackover which traffic moves in both directions. The stretch shown in the drawing comprises two blocks A-D and E-H, separated by a passing siding N. Trafiic through block E-H from east to west is governed by a plurality of .signals S, S and S located at intervals through the bloclgand traffic through the same block from west to east is governed by a similar set of signals S S ands? Traffic through block A--D from east to' west is similarly governed by a set of signals S, S and S while traffic through this block from west to east is governed by signals S, S and S Westbound traffic into the passing siding N is governedby a signal S and eastbound trafiic into this siding is g0verned by asignalS As here shown, each signal is of the threeposition type capable of giving tl'ireelindications, namely, procoed when the semaphore arm is vertical,

caution when the semaphore arm is inclined, and stop when the semaphore arm is horizontal. I do not desire, however, to limit myself to signals, of this particular character.v

The blocks A.--D and E'H are divided ,by insulated joints 3, into a plurality of successive sections AB, B.C, etc, and, as here shown, a pair of opposing signals is located at the junction of each two adjacent sections. I do not wish, however, to be limited to this specific location of the signals.

The control of ,the signals, is as follows:

section A-B, signal S movesto the caution .osition and whenthe train aasses out n 7 I I 1 of section B,C this signal returns to the proceed position. Signal S moves to the stop position when thetrain enters section BC, and this signal returns to the caution" position when the train has passed out of this section. When the train. enters sectior C-D, signal S moves to the stop position, and when the train passes out otsection CD signal S returns to the caution position and signal S returns to the proceed EH are controlled in the same manner as "turn to the proceed position.

the signals for block AD The operation of the signals which I have just outlined may be accomplished by apparatus and circuits of various types. Severalsuch forms of'apparatus andcircuits are now known in the art, and, consequently, a detailed explanation of the means for controlling the signals is not considered necessary. A signaling system of "the type described is commonly knownas absolute permissive signaling.

lVhenever signal S indicates stop, signal S indicates caution, and whenever signal S indicates stop, signal S? indicates caution. It is desirable, however, for reasons which are well understood in the art, that when an eastbound train occupies any part'of the block A-D, signal "S as well as signal should indicate caution, but that when a westbound train has passed point Q in section CD, thus allowing signal S to move to the caution position, signal S should re- One method of accomplishing this selective operation of signal S will be explained hereinafter. Referring now to Fig. 2, I have here shown the portion of the traclc' between points D and F, together with all of the apparatus and circuits associated therewith for accomplishing the objects of my invention. The track section D'E,which includes the passing'sidingN, is provided with a track circuit comprising a track battery 7) adjacent point E and a track delay T 9 adjacent point D. The section T l-J1 is divided into two sub-sections ll-J and J--l and each subsection is provided with a track circuit comprising a battery 6 and a track relay designated T or p of poi'nttD is provided with a track circuit of which only the track relay T1 is shown in the drawing, and similarly the section to the of point F is provided with a track circuit of which only the track relay T is T; The section to the west.

shown in the drawing. The track battery 6 for each track circuit isconnected across the rails in series with the secondary of a transformer designated by the reference character U with a suitable exponent, the functions of and contact 8 of relay R to terminal C of" the same source of current. The proceed indication circuit for this signal is'from terminal B through the fro'nt'point of contact 4:, wires 5 and 9, polarized contact 10 of relay R ,wire 11, operating mechanism of'signal S wire7, and contact 8 to terminal C of the same source of current. It will be seen, therefore, that signal S will indicate proceed when relay R isenergized in such direction that contact 10 is closed, which I will term the normal direction of energization, and that'this signal will indicate caution when relay R is energized in the other or reverse direction. Belay R is energized in normal orreve'rse direction ac-' cording as it is supplied with current of normal or reverse polarity.

The control of each. signalgby the corresponding k control of signal Stjust explained;

Signal relay R is controlled by contact 12 oftrack'rel'ay T and by other apparatus in the block AD in suchmannerthat this relay isde-energized when an eastbound train enters this block, but that this relay becomes energized in reverse direction after a westbound train passes signal S and in normal direction after a westbound train passes signal S. f

Signal relay R is provided with a circuit which passes from terminal B of a suitable source of current througlrp ol'e-chan'ger P wire 13, contact l l of track relay T wire 15, contact 16 of track relay T wire 17,

signal relay B 'is similar to thewinding of relay R common wire Oand pole-changed P to terminal C, of the same source of current. Pole-changer P is operated by signal S in such manner that current of normal polarity is supplied to relay B when signal S in the proceed or cantion position, but that. current of'rev'erse polarity is supplied torelay B when signal S is in the stop position. Relay R is, of course, (lo-energized when either track relay T or T isopen.

Signal relay B iscontrolled by a polechangin'g relay K", thecir'cufit being from terminal B of a suitable source of current circuit for relay K is v with a second branch, aroundcontacts 20 through front point of contact 44 ofrelay K wire so, contact 16 of traclr relay T wire 17, contacte'i8 of track relay T wire e18, winding of relay R common-wire wire 19, and front point or contact 50 of: relay K" to terminal G of the same source of current. The current which isthus supplied to relay R is of normal polarity, so that signal S indicates proceed. .When relay K is de-energized the circuit for relay R is the same as before, except that the polarityof the current flowing therein is reversed, so that signal S will indicate caution. Relay R is, of course, ale-energized when either tracl; relay T or T is open.

Relay K is provided with a circuit which passes from terminal 13 through polechanger 1, wires 112 and 150, contact operated by signal S wires 21 and 22, contact 23 operated by signal S wire 24, winding of relay K wire 25, and common wire 0 and polechanger P" to terminal C.

This circuit is provided with a branch around contact 20 of signal S, which branch passes from wire 112 through. wires 151 and 153, contact 29 of relay R and wires and 28 to wire 22. The signal-operated contacts 2i) and 23 are each closed when the be open whenever signal relay R" isopen,

that is, whenever a train occupies section L D, and whenever an eastbound train occupies any portion of block rit -D. 'The provided, however,

and 29, which branch passes from wire 112 through wires 151 and 152, contact 26 of an auxiliary relay L, and wires 27 and 28 to wire 22. Relay L isprovided with a pick-up circuit which passes from terminal B, through contact operated by signal S",

wire 36, back contact 37 of track relay Ti, wires 38 and 39, winding of relay L wire 10 and back contact 11 of signal relay R to terminal C. This circuit is closed when a westbound train enters section CD, be cause at that time contacts 37 and 11 become closed before contact 35 opens. The

pick-up circuit for relay L is not closed,

however, (lillln the aassa 'e of an eastbound train along the track, because relay R is opened by such a train before track relay TY opens. and so contact 35 is open when contact 37 of track relay T becomes closed. Relay L is provided with a holdingv circuit which passes from battery terminal B, through contact 42 of the. relay itself, wires and windin of relay L wire l-.0 and back contact 41 or signal relay R9 toterrninal it "follows, therefore, that when auxiliary relay L is closed by a westbound train it remains closed until signal relay R becomes energized, that is, until the rear of the train passes out of section C-D. It will. be seen, .thereiore, that when aneastbound train enters block A'D, the opening of signalrelay R and the consequent movement ofsignal S to the stop position cause the pole-changing relay K to become deenergized so that signal S moves to the caution position. -l/Vhen a westbound train passes along the tr'acln'however, relay K becomes energized as soon as the train passes point Q in section C D, due to the fact that stick relay L has been closed, so

that signal S then returns to the proceed pos1t1on.

Considerin now the eastbound signals, signal relay l-t 'is controlled by contact 51 of track relay T and by suitable apparatus in sectionsrF G and G 1, so that this relay is opened when a. westbound train enters block E-H. Signal relay R is prothrough pole-changer I operatedby signal S, wires 52 and 53, contact 5 1 of relay ll, wires and 56, contact 570i track relay. T", wire 58, contact 59 of track relay T wire 59, winding of relay R common wire 0 wire 60, and pole-changer l to terminal C of the same source'of current. This circuit is provided with a bran-ch around contact 54 of relay it, which branch passes from wire 52. through wires 61 and (32, contact 63 0'1 auxiliary relay L and wire (34 to wire 56, f Relay Ifis controlled by track relay T, signal relay R and by signal S, the circuits beingsubstantially the same as thecireuits for relay L The circuit for signal relay R is controlled by pole-changer P contact 18 of track relay TT and contact 19 of track relay T the circuit being similar to the circuit for signal relay R Pole-changing relay K which controls signal S (not shown in.

Fig. 2), is controlled by contact 31 of signal S and contact 32 of signals, the

main circuit for this relay being similar to the circuit hereinbefore traced for polc changing relay K The circuit for relay K is provided with a branch around si; nal-operated contact 31, including contact 33 of relay R and with av second branch which includes contact 34 oi auxiliary relay L3. eThe circuits for relay lfiv are similar to the circuits tor the corresponding r lav L".

direction, so that signal S moves to the caution position; The opening of relay R together with the movement Oi signals to r the stop position opens the circuit'tor pole:

When an eastbound train enters block lll) changing relay 'K (relay L heing open), so

7 that relay il 'JlDQ POIIBS energized in the re- Ill i or point 1)., however, traclr verse direction, thereby causing signal S7 to move to the caution position. \Vhen such train enters the right hand sub-section of section C-D, theopening of traclr relay T opens the circuit for relay il so that signal S moves to the stop position; As the train enters section DE, the opening of track re lay T opensthe circuit. for relay R so that signal ti moves to the stop position, and when the entiretrain has passed point D, relay It" again closes,'so that signal S returns to the proceed position. As the train enters subsection 1*] J, the opening of track relay T opens the circuit for relay P, so that signal S moves to the stop position, and the same track relay opensthe circuit for relay it so that signal 3 moves to the stop position. When the entire train passes out of section D-l l, the consequent closing of track relay T permits relay R to close,

so that signal S returns to the proceed position. When the train passes point J,

relay it? closes in reverse direction. so that signal S moves to the caution position. As the train passes point F signal S moves to the stop position and signal S returns to the proceed position. Signal S also returns to the caution position, so that signal S moves to the proceed position.

When a Westbound train enters block l*]l*l, it causes relay R to open, so that signal S moves to the stop position. The open ing of relay or causes relay R to open, so that signal S also moves to the stop position. The consequent operation. of polechanger P causes relay A, to become energized in the reverse direction, so that signal S moves to the caution position. .As the train enters sub-section J-F the opening oi track relay T opens the circuit for relay P so that signal S moves to the stop position. The subsequent opening of track relay T due to the entrance of the train into subsection. ill-J opens the circuit of relay B so that signal S moves to the stop position. When the train enters section ll-E, the opening of track relay T opens relay R so that signal S moves lo the stop position. The consequent opening or" contact operated by signal vFfl opcns the circuit for relay .K so that when the entire train has passed out of section i l-l signal iii returns only to the caution position. As the train passes point D auxiliary relay ll heroines closed. The passage oi the train into the firstsubsection of l.) does not per section w mit relay R to'close, because this relay is controlled, by track relay T litter the train leaves the first sub-section to the left 7 relay T closes so that relay R then becomes energized in reverse direction and signal 5 moves to the caution position. The circuit for relay K is then closed at contact 23 and contact 26 so that this relay t hen becomes energized this causes signal relay R to be energized in the normal direction so that signal S? returns to the proceed posit-ion.

Each section of track is'provicled with means for supplying alternating vehicle governing current to the is of the sec 1 tion at both ends. Considering section 13 E.

for 'e'nainple, this current is supplied to'the battery end through themediumhr aftrans tormcr U, the secondary of which isinchided in the track circuit between the battery t and the upper track 'rail'Q, and the primary oft which is'at times supplied with alternating cu'rrent'as explained hereinafter. At the relay end of this track section the vehicle governing current is furnished by a transformer U these'c'ondary of which is connected across the rails of the section in multiple with the track relay T. A resistance 12 i, is included between the secondary of transformer U 'and one track rail to pre-.

primary of transformer V is at times con-- nected with transm ssion mains '65ancl 66 to which alternating current is constantly supplied by' a generator V. The circuit for the primary of transformer V is fron rtrans mission main 65, through. wires 67 and 68,

contact 70-6 9, wire 71, contact 72-73,=wire' 74, primary or" transformer V and wire 75 to transmission main 66. It will be seen that this circuit is closed only when signal S is at stop and signal S is in the proceed or caution 'vosition. In other words, vehicle governing current is supplied to the rails at the right-hand end of section D.-E only when a trainmoving toward the east is approachingsignal S and section E--F is unoccupied. v

The circuit for the primary of trans former U? is from transmission main 65, throughwilies 76 and 7,7, contac 7879, wire 80, contact 82-81, wire 83, primaryof transformer U and Wires 84 and S4 to transmission main 66. This circuit is closed only when signal S? is at stop and signal S is in the caution or proceed position; in other words, vehicle governing current is supplied to the rails at the, left-hand end of section D 11 only when a westbound train is approaching signal S and section C 'D is unoccupied.

Considering new section E F, the circuit for the primary of transformer U is from transmission main 65, through wires 85 and 86, contact 8788, wire 89, contact 90-91,

ratus shown in Fig. 2 is arranged for c0- wires 92 and 93, primary of transformer U and wire 94 to transmission main 66. The circuit for the primary of transformer U* is the same as the circuit for the primary of transformer U up to and including wire 92, and it then passes through wire 95, primary of transformer U and wire 96 to transmis. sion main 66. It will be seen, therefore, that transformers ll and U are energized only when signal is at stopand signalS is in the caution or proceed position; that is, only when a train moving toward the east is approaching signal S and the section F-G is unoccupied.

The normal circuit for the primary of transformer U is from transmission main 65. through wires 6'? and 97, contact 98-472, wire 71, contact 6999, wires 100 and 101', contact 102 of pole-changing relay 1 wires 103, 104 and 105, primary of transformer U and wires 106'a-nd to transmission main 66. The circuit for the primary of trans former U is the same as the circuit just traced up to and including wire 104, and it then passes through wire 107, primary of transformer U wire 108 and wire 96 to transmission main 66. It will be seen from the foregoing that transformers U" and U are normally energized only when signal S is at stop and signal S is in the caution or proceed position and pole-changing relay K is energized. The circuits for transformers U and U are provided, however, with a branch around contact 102 of relay K", which branch passes from wire 100 through wire 109, contact 110 ofan auxiliary relay M and wire 1 11 to wire 104. When relay Mlis closed, then, transformers U 'and U will be energized regardless of the-condition of relay K'Q provided that signals S and S are in the positions specified above.

' RelaysM is provided with n. pick-up "circuit which passes from terminal 13 of a suitable source of current through contact 11.3 of auxiliary relay L wire 114, wire 115,

contact 116, wire 117, winding of relay M wire 118, and common wire to terminal C of the same source of current. It follows that relay M will be energized when relay L is closed and signal S is in the proceed position. that is, it will closewhen a westbound train passes signal S provided that signal S is then in the proceed position. Relay M is provided with a holdingcircuit which passes from terminal B through contact 113, wires 114 and-119, contact 120 of signal relay R wire 121, contact 122 of relay B4 wire-123, winding of relay 14, wire 118, and common wireO to terminal C. It follows'that when relay l /I islonce energized by'a westboundtrain-it will remain closed until such train enters section DE, even though relay K may open while the train is in section FF;

It is understood that the trackway appaoperation with suitable vehicle-carried ap-' pairatus which operates to give a proceed.

indication on a vehicle when the vehicle occupies a section of track to which alternating vehicle governing current is supplied tothe rails in advance of the vehicle, and a stop-indication when the vehicle occupies a section to whichsuch current is not suptrain enterssub-section JF, it causes relay M to close. ,Transformers U and U are then supplied with alternating current independently of the contact 1020f pole-changing relay K While this train is in'either sub-section J-F or Pi -J, if an eastbound train should enter block A--D, the conse quent opening of pole-changing relay K would not cause the vehicle governing apparatus on the westbound train to change to a stop. indication. If, however, the eastbound train should get into sub-section Q D while the westbound train is still in section E-F, the consequent opening of track relay T would-open the circuit of relay R and contact 120 of the latter relay would open the stick circuit for relay M so that the apparatus on the westbound train would then give a stop indication.

One important feature of my invention is the fact that I accomplish the control just explained by means of an auxiliary stick relay M, thereby eliminating the necessity for providing the pole-changing relay K with a stick circuit. This feature is anadvantage when, as in the present disclosure,

relay K is included in the circuit with a pole-changer sothat this relay is at times energizedby current of one polarity and at other times by current ofthe other polarity as it is'not always desirable to apply a stick circuit to a' relay which is controlled in this manner. a

Another important feature of my invention is the fact that-normally thecircuits for the primaries-of the transformers U:are open, these circuits being closed only while a train is approaching and passing through the corresponding section of track. It follows, therefore, that there is no unnecessary consumption of energy from the alternating 1,

current generator W. V I p Although I have herein shown and described only one form of apparatus embody ing my invention, it is rmderstood that vari ous changes and modifications may be made therein within the scope of the appended claims without departing from the spirit and scope of my invention.

Having thus described my invention, what 1 claim is:

1. In combination, a stretch of railway track comprising two blocks separated by a passing siding, the first block being'provided with a. track section adjacent said siding, a signal for governing traiiic through said section towards thesiding, arelay for controlling said signal, means for opening said relay when a train enters the second track comprising two blocks separated by a block moving towards the siding,a second;

trolling said signal, means for opening said relay when a train enters the second block moving towards the siding, a second relay, a pick-up circuit for said second relay including a contact closed when the siding and the secondbloclr are unoccupied, a holding circuit for said second relay including a contact of the relay itself contact which is open only when a train is in or adjacent the siding, and means controlled said second relay when closed. for supplying vehicle governingcurrent to said section.

3,111 combination, a stretch of railway track comprising two blocks separated'by a passing siding, the first block being provided with a track section ad acent sa d sid ng,

a signal governing trailic through said section towards said" siding, a relay "for con trollingsaid signal, means for opening said relay when a train enters the second block moving towards said. siding, a second relay,

neans for holding said second relay closed" while a train moving towards said s1 ding occupies said track section, even though a second train moving in the opposite direction subsequently enters said second block, means controlled by said first relay when closed for supplying vehicle governing currentto said section, and means controlled by'said second rel'a when closed for su )l' in ve-' hicle governing current to said section independently of the'lirst relay. p

i. In combination, a stretch of railway and a passing siding, the first block being provided with a track section adjacent said siding, a signal i'orgoverning trafiic through said section to\\ 'ards the siding, a relay for controlling said signal, means for opening said relay when atrain enters the second block moving towards the siding, a second relay, means for closing said second relay when a train moving towards the siding enters said section provided the second block is not then occupied by a train moving towards the siding and for subsequently holding the second relay closed until the train enters the siding even if a train moving in the opposite direction enters the second block in the mean time, and means controlled by said second relay when closed for supplying vehicle governing current to said section.

5. Railway trailic controlling apparatus comprising a section of railway track, a track circuit for said section including a source of direct current and a track relay, and means controlled by a train approach ing said section for supplying vehicle governing alternating current to the rails of the section in series with said source of direct current. i r.

6. Railway trafic controlling apparatus comprising a section of railway track, a track 1 circuit for said section including ;asource of direct current and a track relay, a trans former whose secondary is-included in the connection between one track rail and said source, and means controlled by a train ap preaching said section for sup'plyi ng'vehicle governing alternating current to the primary of transformer.

'Z'LRailway traflic controlling apparatus comprising a section of railway track, a

track circuit for said section including a source of d rect current and a track relay, a transformerwhose secondary is included in the connection between one track rail and I said source, and means controlled a train approaching sa d sect on for supplying yeihicle governing alternating current to the primary of said transformer when the track on the opposite side of said section is unoccupied. v r r I 8. Railway trafiic controlling apparatus comprisinga section of railway track, a

track circuit for said section including a source of direct current and a track-relay, and means controlled by a trainapproaching said section for supplying vehicle governing alternating current to the rails of the section 111 series with sa d source of direct current. when the track on the opposite side-of said section is unoccupied. I I.

9; Railway traffic controlling apparatus comprising asection of railway track over which trailic moves in both directions, and means controlled by a train approaching said section from either direction for connecting a source of vehicle governing alternating current across the rails of the section at the track circuit for said section including a source of direct current connected across the rails at one end of the section and a track relay connected across the rails at the other end of the section, a transformer whose secondary is included in said track circuit be tween one track rail and said sourceof direct current, and means controlled by a train approaching said section and about to enter the section at the track relay end for supply- .ing alternating current to the primary of said transformer provided that the track on the opposite side or" said sectionis unoccupied.

11. Railway traflic controlling apparatus eomprisin fa section of railway track, a track circuit for said section including a source of direct current and a track relay, a roadside signal for said section controlled by said track relay, and means controlled by a train approaching said section for connecting a source of vehicle governing alternating current across the rails of said section at the end farthest from the train,

12. Railway traffic controlling apparatus comprising a section of railway track, a track circuit for said section including a source of direct current, and a track relay, and means controlled by a train approaching said section for connecting a source of vehicle governing alternating current across the rails of the section in multiple with said track relay.

13. Railway traffic controlling apparatus comprising a track divided into a plurality of successive sections, a track circuit for each section including a source of direct current and a track relay, signals for the sections controlled by said track relays, and means controlled by a train approaching each section for connecting a source of vehicle governing alternating current across the rails of the section at the end of the section farthest from the train provided thatthe next section adjacent said latter end is unoccupied.

14. In combination. a stretch of railway track comprising two blocks separated by a passing siding, the first block being provided with a track section adjacent said siding. a signal for governing traffic through said section toward the siding. a relay'for controlling said signal in such manner that when the section is unoccupied the signal indicates proceed or caution according as the relay is energized or de-energized, means for de-energizing said relay when a train enters the second block moving toward the siding, a second relay, means for closing said second relay when a train moving toward the siding enters said section provided the second block is not then occupied by a train moving toward tie siding and for subsequently holdin g the second relay energized until the train enters the siding even it a train moving in the opposite direction enters the second block in the meantime, and means controlled by said second relay whenenergized tor supplying vehicle governing current to said section. Y i

15. In combination, av stretch ofrailway track comprising two bloclrs separated by a passing siding, the first block being provided with a track section adjacent said siding, a

relay controlled by tratlic conditions in the second block in such manner as to be closed when the block is unoccupied and opened when a train enters the second clock moving toward the siding, means controlled by said relay for supplying vehicle governing cur rent to said track section, asecond relay, means for closing said second relay when a train enters said section moving toward the siding and for subsequently holdingitclosed even it a second train moving in the opposite direction enters the second block, and means for supplying vehicle governing current to said track section independently of said first relay when the second relay is closed.

16.'In combination, stretch of railway track comprising two blocks separated by a passing siding, the first block being provided with a track section adjacent said siding, a relay controlled by tralii'c conditions in the second block in such manner as tobe closed when the block is unoccupied andwhen a train moving away from the siding has reached a given point in the second block but opened 'when a train enters the second block moving toward the siding, means controlled by said relay for supplying vehicle governing current to said track section, a second relay, means for elosing said second. relay when a train enters said section moving toward the siding and for subsequently holding it closed'even ita second train moving in the opposite direetion enters the second block and means tor supplying vehicle governing current to said. track section inde i endently 01 said first relay when the second relay is closed.

17. In combination, a stretch of railway track comprirnng' two blocks separated by a passing siding, the first bloclt being provided with track section adjacent said siding, a relay controlled by tratlic conditions in the second block in such manner as to be closed when the block is unoccupied and opened whena train enters the second block moving toward the siding, means tor supplying vehicle governing current to said track section when a train occupies the section moving toward the siding it said relay is closed, a second relay, means for closing said second relay when a train enters said section moving toward the siding and for subsequently holding it closed even if a second train moving in the opposite direction enters the second block, and means for supplying vehicle governing current to said track section independently of said first relay when the second relay is closed.

18. In combination, a stretch of railway track comprising two blocks separated by a passing sidingythe first block being provided with a track section adjacent said siding, means operating when a train moving toward the siding occupies said track section for supplying vehicle governing current to the track section if the secondblock is unoccupied but not if the second block is occupied by a train moving toward the siding, a normally open stick relay functioning when closed to continue the supply vehicle governing current to said track section even if a train enters the second block moving toward the siding, and means for closing sai'd relay when a train moving toward the siding enters said section provided the second block is not occupied by a train moving toward the sidif a second train in the meantime enters the second block moving toward the siding.

19. In combination, a stretch of railway track comprising two blocks separated by a passingsiding, the first block being provided with a track section adjacent said siding, a relay controlled by trafiic conditions in the second block in such manner as to be closed when the block is unoccupied and opened when a train entcrs the second block moving toward the siding, second relay, means for closing said second relay when a train enters said section moving toward the siding and for subsequently 'hol'cling it closed even if a second train moving in the opposite direction enters the second block, and means controlled ointly by said two relays for supplylng vehicle governing current to said track' section.

V In testimony whereof I; my sig nature. 7 1

Roniiinn antenna. 

